POS0580 TRENDS IN THE OCCURRENCE OF ISCHEMIC HEART DISEASE OVER TIME IN RHEUMATOID ARTHRITIS: A RETROSPECTIVE COHORT STUDY FROM NORWAY OF 1821 PATIENTS FROM 1972 TO 2014
Authors: C. L. Alsing, T. W. Nystad, J. Igland, C. G. Gjesdal, H. Midtbø, G. S. Tell, B. T. Svanes Fevang
Journal: Annals of the Rheumatic Diseases (2022)

Background Previous studies have shown that rheumatoid arthritis is associated with a 1.5 to 2.0 times increased risk of acute myocardial infarction (AMI) and ischemic heart disease (IHD) compared with the general population [1,2]. RA treatment has improved vastly over the last two decades, due to the focus on early and aggressive treatment and the use of synthetic and biologic DMARDs. Several studies have documented higher rates of remission and better long-term outcomes in patients with early introduction of DMARDs [3]. This “window of opportunity” may also be a critical phase for intervention against the development of atherosclerosis in RA. There is little information about the occurrence of AMI and IHD in RA patients diagnosed after the introduction of modern RA treatment. Objectives To evaluate trends of AMI and IHD in RA patients compared with the general population over time. Methods We performed a retrospective cohort study of 1821 RA patients diagnosed from 1972 to 2013. The total population of Hordaland, Norway was used as a comparison cohort. Information on AMI and IHD events was obtained from hospital patient administrative systems or cardiovascular registries during 1972-2014. Aggregated counts of AMI, IHD and population counts of the comparison cohort were used to calculate expected counts of AMI and IHD in the RA cohort per 5-year age group, sex and calendar year. We then used Poisson regression with expected counts as an offset to estimate standardized event ratios (SER) as a measure of excess events. Results The difference in events (excess events) in RA patients compared with the general population declined on average 1.3% per year for AMI and 2.3% for IHD from 1972 to 2014. There was no significant excess AMI (SER 1.05, 95% CI 0.82–1.35) and IHD events (SER 1.02, 95% CI, 0.89–1.16) for RA patients diagnosed after 1998 compared with the general population. Conclusion RA patients have historically had an excess risk of IHD compared with the general population. Our study did not find excess AMI or IHD events in RA patients diagnosed after 1998. Our findings may reflect improved management of RA, CVD prevention or changes in the case-mix of RA patients over time. References [1]Schieir O, Tosevski C, Glazier RH, et al. Incident myocardial infarction associated with major types of arthritis in the general population: a systematic review and meta-analysis. Ann Rheum Dis 2017; 76 :1396–404. [2]Han C, Robinson DW, Hackett MV, et al. Cardiovascular Disease and Risk Factors in Patients With Rheumatoid Arthritis, Psoriatic Arthritis, and Ankylosing Spondylitis. J Rheumatol 2006; 33 . https://pubmed.ncbi.nlm.nih.gov/16981296/ (accessed 2 Jul 2020). [3]Monti S, Montecucco C, Bugatti S, et al. Rheumatoid arthritis treatment: the earlier the better to prevent joint damage. RMD Open 2015; 1 :e000057. Figure 1. Excess AMI and IHD events in RA patients compared with the general population. RA patients are divided into three groups by the time of RA diagnosis. End of follow-up was set to 1 year after the end of each diagnostic period (1986, -99 and 2014 respectively) to allow for equal RA duration between groups. Point estimates are standardized event ratios comparing the number of events in the RA cohort to the expected number of events calculated from reference rates in the general population and standardized for age, sex and year of the event. All estimates are given with robust 95% confidence intervals (CI). Both the RA and general population were obtained from Hordaland, Western Norway. AMI, acute myocardial infarction; IHD, ischemic heart disease. Acknowledgements This work was funded by the Western Norway Regional Health Authority, Marit Hansen’s Memorial fund and Aslaug Andersen’s Memorial fund. Disclosure of Interests Christian Lillebø Alsing: None declared, Tone Wikene Nystad: None declared, Jannicke Igland: None declared, Clara Gram Gjesdal: None declared, Helga Midtbø: None declared, Grethe S. Tell: None declared, Bjørg Tilde Svanes Fevang Speakers bureau: Part of discussion board at UCB conference on spondyloarthritis, Consultant of: Part of advisory board Lilly.